Paeis erb



(No Model.) 2 Sheets-Sheet 1.

' P. EBB.

SCREW PRESSURE BLOWER.

No. 536,925. Patented Apr. 2, 1895.

lgacgir farzErb Wiigzsses UNITED STATES PATENT OF IC PARIS EBB, OFLANCASTER, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO FRANKLIN SUTTON ANDJOHN L. SUTTON, OF SAME PLACE.

SCREW-PRESSURE BLO WER.

SPECIFICATION forming part of Letters Patent No. 536,925, dated April 2,1 895. Application filed December 8, 1893. Serial No. 493,185. (Nomodel.)

\ To all whom it may concern.-

Be it known that I, PARIS ERB, a citizen of the United States, residingat Lancaster, in the county of Lancaster and State of Pennsylvania, haveinvented a new and useful Screw-Pressure Blower, of which the followingis a specification.

My invention relates to a direct pressure blower adapted for use inconnection with forges, cupola and other furnaces, and for use inproducing exhaust drafts, the objects in view being to provide aconstruction whereby back pressure, or pressure in opposition to thedirection of the draft, is prevented, and whereby the current of air isgiven a spiral or twisting movement; and furthermore, to provide aconcentrating casing whereby a blast of uniform density is the result.

Further objects and advantages of this invention will appear in thefollowing description, and the novel features thereof will beparticularly pointed out in the appended claims.

In the drawings: Figure 1 is a perspective View of a blower embodying myinvention. Fig. 2 is a central section of the casing with the fan inposition. Fig. 3 is a central section of the casing with the fanremoved. Fig. 4 is a view of the stationary guard at the inlet end ofthe casing.-

Similarnumerals of reference indicate corresponding partsin all thefigures of the drawlugs.

1 represents the conical casing, which is capered from its inlet to itsoutlet end and is provided with an outlet funnel 2, which is abrupt] ytapered to the nozzle 3. Said casing is provided with perforated ears 4,to facilitate the attachment of the apparatus to a suitable base orsupport, not shown. The casing is provided, upon its interior surface,with spirally-disposed ribs 5, which extend from the inlet to the outletend of the main body of the casing. These ribs terminate at oneend,'opposite the blades 6 of the stationary inlet guard 8; said guardhaving the central hub 9, which" forms one of the bearings for the axialfan-shaft 10. The outer ends of the blades 6 are provided withperpendicular longitudinally-tapered blocks 11, which are secured to theinner surface of the casing, and the blades are spirally-disposed toagree with the spiral arrangement of the ribs.

An outlet guard 12, similar in construction to'the inlet guard abovedescribed, is arranged at the outlet or reduced end of the main portionof the casing,- and is provided with wings l3, and a central hub 14,which forms the other bearing for said axial fan-shaft.

The fan consists of a series of spirally-arranged blades 15, the pitchof which agrees with that of the ribs upon the inner surface of thecasing, whereby, when the fan is rotated in the direction indicated bythe arrows a, in Fig. 1, the air which enters through the spaces betweenthe wings ofv the stationary inlet guard is thrown outwardly bycentrifugal force and is caused to travel between the guiding ribs onthe shellof the casing in the direction indicated by the arrows b inFig. 1. The spiral wings of the fan terminate close to the inner edgesof the wings of the guards, and the peripheries of said spiral wingsoperate close to the inner edges of the guiding ribs; and, inasmuch asthe pitch of the spiral wings agrees with that of the ribs, the air isforced, by a positive pressure, in the direction of the ribs.

The wings of the rotary fan are reduced in circumference toward theoutlet end of the blower, such reduction being more abrupt than thetapering of the .walls of the casing, and the guiding ribs are increasedin projection toward the outlet end of the casing to preserve a uniforminterval between the peripheries of the fan blades and the ribs.

The spiral direction of the current of air through the blower assists inthe concentration of the blast and produces a whirling or twistingaction, whereby a blast of uniform density is produced.

From the above description it will be seen that the construction of myimproved blower is simple and that it may be manufactured at acomparatively small cost. Any suitable means for supplying power to theshaft may be employed. It will be seen, furthermore, that inasmuch asthe casing is tapered or conical throughout its length a gradualcompression of the air is attained, instead of allowing this compressionto be accomplished solely at the outlet end of the blower. The

latter construction causes an amount of friction and interference withthe blast which is avoided by the continuously-tapering casing.Furthermore, the conical shape of the casing enables the manufacturer toconstruct the same from a single casting and form the interior ribsintegral therewith, whereby the jointing of two separately-constructedhalves is avoided. It should be noted, also, that the helicalarrangement of the blades 15 causes the blast to be pressed or forcedforward by a steady pressure in that direction, and therefore the blowerdepends upon pressure in the direction of the axis of the cylinder orcasing instead of centrifugal motion, as in those blowers provided withblades or wings which are arranged more nearly parallel with the axis ofrotation. Again, it is apparent that inasmuch as the shaft of the fan ismade of small diameter, and the entire space between the shaft and thewalls of the casing is occupied by the blades, a greater volume of airis received at the inlet end of the casing. Hence a stronger blast isproduced than would be possible if the shaft approximated in diameterthe bore of the cylinder or casing.

Having described my invention, what I claim is 1. In a blower, thecombination of a continuously tapered or conical casing provided withintegral ribs arranged spirally upon its inner surface and increasing inprojection toward the smaller or outlet end of the casing, and a rotaryfan having blades extending spirally from one end of the casing to theother and reduced continuously in diameter toward the smaller or outletend of the casing, substantially as specified.

2. In a blower, the combination of a continuously tapered or conicalcasing, guards located respectively at the inlet and outlet ends of thecasing and each comprising a central hub and a series of radial spacedfiat wings, the planes of which are deflected from any radial planeembracing the axis of the hub, and a rotary fan having its shaft mountedin the hubs of said guards, and having blades extending spirally fromone end of the casing to the other and reduced continuously in diametertoward the small or outlet end of the casing, substantially asdescribed.

3. In a blower, the combination of a conical casing provided upon itsinterior surface with spirally-disposed parallel guiding ribs whichincrease in projection from the inlet to the outlet end of the casing, aconcentrating funnel arranged at the outlet end of the easing,stationary guards disposed at the outlet and inlet ends of the casingand comprising central hubs arranged in alignment, andangularly-disposed wings provided at their outer extremities with blockswhich are secured to the inner surface of the casing, the inclination ofsaid wings corresponding with that of the guiding ribs which terminaterespectively at the edges of the wings, and a rotary fan having itsshaft mounted in said hubs and provided with parallel spirally-disposedwings which terminate contiguous to the inner edges of the wings of theguards and have their peripheries arranged close to the inner edges ofthe guiding ribs, said wings being reduced in circumference toward theoutlet end of the blower, and the pitch of the same being equal to thatof the guiding ribs, substantially as specified.

In testimony that I claim the foregoing as my own I have hereto affixedmy signature in the presence of two witnesses.

PARIS ERB.

Witnesses:

V. K. ALEXANDER, N. D. ALEXANDER.

